AMG ownership update: 7.0% Morgan Stanley, 6.3% Atlanta Capital

Rhea-AI Filing Summary

Affiliated Managers Group (AMG): Morgan Stanley, Atlanta Capital Management Company, and Eaton Vance Atlanta Capital SMID-Cap Fund filed Amendment No. 6 to Schedule 13G reporting beneficial ownership of AMG common stock tied to a Date of Event of 09/30/2025.

Morgan Stanley reported 1,983,387 shares, representing 7.0% of the class, with shared voting power 1,796,796 and shared dispositive power 1,907,109 (no sole power). Atlanta Capital reported 1,778,903 shares, or 6.3%, with shared voting power 1,608,717 and shared dispositive power 1,707,951 (no sole power). The Eaton Vance Atlanta Capital SMID-Cap Fund reported 1,276,051 shares, or 4.5%, and stated it has ceased to be a beneficial owner of more than five percent.

The filers certified the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control.

Insights

Equity ownership & filings analyst

Passive 13G/A shows 7.0% and 6.3% stakes; one holder fell below 5%.

This amendment lists beneficial ownership in AMG by three related reporting persons. Morgan Stanley reports 7.0% (1,983,387 shares) with only shared voting/dispositive power, while Atlanta Capital reports 6.3% (1,778,903 shares), also with shared powers. The Eaton Vance Atlanta Capital SMID-Cap Fund reports 4.5% and notes it is no longer above the five percent threshold.

The certification states the positions are held in the ordinary course and not to influence control, consistent with a passive 13G. Actual market impact depends on future portfolio decisions and does not follow from this filing alone.

The 09/30/2025 event date anchors these ownership levels. Subsequent filings may update holdings and percentage calculations if share counts or positions change.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 6)

AFFILIATED MANAGERS GROUP, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

008252108

(CUSIP Number)

09/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Morgan Stanley

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,796,796.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,907,109.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,983,387.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

7.0 %

12

Type of Reporting Person (See Instructions)

HC, CO

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Atlanta Capital Management Company, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,608,717.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,707,951.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,778,903.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

6.3 %

12

Type of Reporting Person (See Instructions)

IA, CO

SCHEDULE 13G

CUSIP No. 008252108

1

Names of Reporting Persons

Eaton Vance Atlanta Capital SMID-Cap Fund

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

MASSACHUSETTS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,276,051.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,276,051.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,276,051.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

4.5 %

12

Type of Reporting Person (See Instructions)

IV

Comment for Type of Reporting Person: As of the date hereof, Eaton Vance Atlanta Capital SMID-Cap Fund has ceased to be the beneficial owner of more than five percent of the class of securities.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: AFFILIATED MANAGERS GROUP, INC.
(b)	Address of issuer's principal executive offices: 777 SOUTH FLAGLER DRIVE, SUITE 1401 EAST TOWER, WEST PALM BEACH, FL, 33401
Item 2.
(a)	Name of person filing: 1: Morgan Stanley 2: Atlanta Capital Management Company, LLC 3: Eaton Vance Atlanta Capital SMID-Cap Fund
(b)	Address or principal business office or, if none, residence: 1: 1585 Broadway, New York, NY 10036 ;2: 1075 Peachtree Street, Suite 2100, Atlanta, GA 30309 ;3: One Post Office Square, Boston, MA 02109
(c)	Citizenship: 1: Delaware 2: Delaware 3: Massachusetts
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 008252108
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: See the response(s) to Item 9 on the attached cover page(s).
(b)	Percent of class: 7.0 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See the response(s) to Item 5 on the attached cover page(s).
	(ii) Shared power to vote or to direct the vote: See the response(s) to Item 6 on the attached cover page(s).
	(iii) Sole power to dispose or to direct the disposition of: See the response(s) to Item 7 on the attached cover page(s).
	(iv) Shared power to dispose or to direct the disposition of: See the response(s) to Item 8 on the attached cover page(s).
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit 99.2
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. * In Accordance with the Securities and Exchange Commission Release No. 34-39538 (January 12, 1998) (the "Release"), this filing reflects the securities beneficially owned, or that may be deemed to be beneficially owned, by certain operating units (collectively, the "MS Reporting Units") of Morgan Stanley and its subsidiaries and affiliates (collectively, "MS"). This filing does not reflect securities, if any, beneficially owned by any operating units of MS whose ownership of securities is disaggregated from that of the MS Reporting Units in accordance with the Release.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Morgan Stanley

Signature:	Christopher O'Hara
Name/Title:	Authorized Signatory, Morgan Stanley
Date:	11/07/2025

Atlanta Capital Management Company, LLC

Signature:	Kelly Williams
Name/Title:	Authorized Signatory, Atlanta Capital Management Company, LLC
Date:	11/07/2025

Eaton Vance Atlanta Capital SMID-Cap Fund

Signature:	Kelly Williams
Name/Title:	Authorized Signatory, Eaton Vance Atlanta Capital SMID-Cap Fund
Date:	11/07/2025

Exhibit Information

EXHIBIT NO. EXHIBITS ------------------ ------------------------------------ 99.1 Joint Filing Agreement 99.2 Item 7 Information * Attention. Intentional misstatements or omissions of fact constitute federal criminal violations (see 18 U.S.C. 1001).

FAQ

What ownership did Morgan Stanley report in AMG (ticker: AMG)?

Morgan Stanley reported 1,983,387 shares, representing 7.0% of AMG common stock, with shared voting power 1,796,796 and shared dispositive power 1,907,109.

What did Atlanta Capital Management report for AMG?

Atlanta Capital reported 1,778,903 shares, or 6.3% of the class, with shared voting power 1,608,717 and shared dispositive power 1,707,951.

Did any holder fall below 5% ownership of AMG?

Yes. Eaton Vance Atlanta Capital SMID-Cap Fund reported 4.5% (1,276,051 shares) and stated it has ceased to be a beneficial owner of more than five percent.

What is the event date for these AMG ownership figures?

The filing lists a Date of Event of 09/30/2025.

What type of filing is this for AMG?

It is a Schedule 13G/A (Amendment No. 6), a passive beneficial ownership report.

Did the filers indicate any intent to influence control of AMG?

No. They certified the securities were acquired and are held in the ordinary course of business and not to change or influence control.